Picker stick check strap for automatic looms



Nov. 12, 1940. c. c. BOND 2,221,281

PICKER STICK CHECK STRAP FOR AUTOMATIC LOOMS Filed June 22, 1938 INVENTO Wm 1 flTTOR/VEY Patented Nov. 12, 1940 UNITED STATES PATENT orrlcc PICKER STICK CHECK FOR AUTO- MATIC LOOMS Charles Carter Bond, Elkins Park, Pa, assignor to Charles Bond Company,

Philadelphia, Pa., a

6 Claims.

The invention relates to improvements in check straps for the picker sticks of automatic looms or for other oscillating parts of these and generally comparable mechanisms in which it is desired to yieldingly check the movement of the oscillating part at the opposite limits of its stroke.

Thus automatic loom picker sticks oscillating in a vertical plane have heretofore frequently been provided with check straps made from either rectilinear or arcuate strips of leather arranged to form a substantially horizontal loop within which the picker stick can move, the ends of the strap being usually bolted together and to the loom frame.

When such straps, however, are made from rectilinear pieces of leather they become distorted and torn after a short period of usedue to the fact that at the moment of check the stick is at an angle to the loop axis and strikes the strap only at its upper edge, repeated blows of this character tearing the strap in a relatively short time. This effect is alleviated to some extent by using an arcuate strap which when fixed in a loop about the picker stick provides an angular surface'for contact of the latter at the limits of its travel, thereby minimizing the tearing efiect of the stick blows upon the strap at the loop ends, but with this arrangement the strap as a whole is subjected to twisting stresses due to the fact that the blows of the picker stick are resolved through the strap against the strapholding bolt along non-parallel lines, and the strap is therefore apt to be'torn elesewhere than atthe points of contact of the picker stick with the loop ends before it is worn out at these points. Moreover, cutting the picker stick check straps in arcuate form results in material wastage of leather, and as grain leather of high quality is required, the cost of production of the straps is consequently rendered unduly expensive.

In accordance with my invention, however, I provide a. novel check strap which is cut from the hide in rectilinear form and therefore with but a minimum of waste in obtaining a number of the straps from a single hide, and which when properly installed in the loom in association with the picker stick provides at the ends of its loop a plurality of points for contact with the stick while the blows to which it is subjected at the opposite ends of the travel of the latter are resolved against the strap holding bolt in precisely opposite directions along parallel lines, thereby substantially minimizing all tearing effect of the picker stick blows.

It is therefore a principal object of the invention to provide a picker stick check strap of novel construction adapted to operate with maximum eificiency throughout a long period of useful life, thus minimizing the frequency with which replacement is required, yet of such form that wastage of leather in cutting out a plurality of the straps is maintained at a minimum.

Other objects, purposes and advantages'of the invention will be understood or will appear from the following description of a preferred embodiment thereof as illustrated in the accompanying drawing, in which:

Fig. 1 isa top plan view of the in a loop as when installed in tion on a loom;

. Fig. 2 is a section thereof on the line 2-2 in Fig. 1 with the picker stick of the loom indicated in dot and dash lines at the opposite limits of the travel; and

Fig. 3 is a perspective view on a reduced scale of the strap when laid out flat or substantially so prior to being formed into a loop for, attachment to the loom.

Referring now more particularly to the drawings the strap l, which is made of relatively heavy leather and preferably about 22 inches in length and 1% inches in width, has a slit 2 extending midway between its lateral edges from adjacent one end to its opposite end thus forming in effect a pair of narrow strips 3, l, integrally connected adjacent one end, the strip 3 being longer than the strip 4 so that when their free ends are secured together, as by staples strap arranged its normal posi- 5, in substantial registry with each other, the

strip 3 is somewhat fuller than the strip 4. Ad-

jacent the opposite ends of the strap as a whole I provide slots 6 adapted for the reception of a bolt 1 which with the aid of a washer 8 holds the strap to the loom when extended through the slots 6 into a threaded hole in a' fixed bracket (not shown) on the loom and set up, the slots providing a capacity for adjustment of the length of the loop formed by the strap.

As is evident from Figs. 1 and 2, when properly positioned on the loom my check strap .provides adjacent each end of its generally ellipsoidal loop vertically spaced edges 9, ill for contact with the picker stick, the strap being so arranged that the strip 3, forming the longer,

loop, is further than strip 4 from the center of oscillation of the picker stick to compensate for the angularity of the latter at the opposite limits of its travel. The picker stick thus strikes the upper edge 9 of the strip 3 and the upper edge ID of the strip 4 substantially simultaneously, the points of contact of these edges with the picker stick at the opposite ends of the loop lying in spaced planes parallel to each other and normal to a radial plane passing through the axis of oscillation of the picker stick and the axis of the bolt 1. It therefore follows that the check strap is subjected only to tension by the blows of the picker stick and this tension is resolved in rectilinear and precisely opposed directions substantially horizontally against the bolt I where it clamps the strap to the loom; there is thus little or no tendency to tear the strap at any point while the distribution of the force of the blow of the picker stick between two spaced edges rather than one at each limit of its travel minimizes the tearing of the ends of the loop under the force of repeated blows of the stick. The loops formed by the strips 3 and 4 when the check strap is in operative position have minor axes of approximately equal length and the picker stick usually does not engage them adjacent the ends of these axes which are in substantial vertical alignment, but the major axis of the loop formed by the strip 3 is somewhat greater than that of the loop formed by the strip 4, due to the greater length of the strip 3, which permits the arrangement of the loops as just described to be attained.

In the manufacture of my check strap a plurality of elongated strips of suitable width may be cut from a single hide in such a way that no waste is produced from between adjacent strips, as all but the two end transverse cuts in the hide form side edges for each of a pair of adjacent straps; the waste of leather inevitable in cutting a plurality of nesting arcuate straps from a single hide is thereby eliminated. At the time the straps are being cut from the hide or subsequently thereto the slit 2 may be made to define the strips 3 and 4, and the free ends of these can then be so positioned relatively to each other as to provide the desired fullness in the strip 3 and their free extremities then evened off, either before or after the staples 5 or other securing means have been applied to hold them together in transverse alignment. The slots 6 are formed usually after the ends of the strips have been fastened together and, if desired, by separate punching operations, and the completed strap is then ready for use.

While the method of manufacture just explained produces small pieces of scrap leather of the width of the strip 4 and in length corresponding to the difference between the length of the strips 3 and 4, these are so small as to be of negligible importance but even this small amount of waste can be eliminated by cutting double length pieces to make pairs of straps end to end and separating them, after making a slit 2 of suitable length in the double strap, by making two transverse cuts extending oppositely inwardly to the slit at points longitudinally separated by a distance equal to the desired difierence in length of the strips in each strap. Thus the projection of the strip 3 beyond the strip 4 in one check strap compensates for the similar projection of the corresponding strip 3 in the other check strap, and substantially no wastage whatever is incurred except that arising from the irregular shape of the hides, disregarding of course the small pieces inevitably reduced to scrap leather in the production of the slot 3.

While I have herein described one embodiment of my invention with considerable particularity it will be understood that I do not desire or intend in any way to limit or confine myself thereto or thereby as changes and modifications in its form, structure and arrangement will readily occur to those skilled in the art and may be made if desired without departing from the spirit and scope of the invention as defined in the appended claims.

Having thus described my invention I claim and desire to protect by Letters Patent of the United States:

1. A picker stick check strap comprising an elongated piece of flexible material having substantially rectilinear parallel side edges and a rectilinear median slit extending from adjacent one end to its opposite end, the individual strips thereby formed being of diflerent length and means securing the free ends of the strips together in substantial transverse alignment, the strap having slots adjacent its ends adapted for the reception of means for securing it to a loom whereby when so secured with said slots in juxtaposition the strips are formed into closed loops of different peripheral length.

2. A picker stick check strap comprising a piece of flexible material having side edges extending in substantially parallel planes, a slit extending from adjacent one end to the other end in an intermediate plane substantially parallel to said first planes and slots adjacent the ends of the strap, and means spanning the slit adjacent the slitted end operative to maintain the adjacent portions of the strap on opposite sides of the slit in substantial engagement with a greater length of one of said portions than of the other between said means and the opposite end of the strap.

3. A picker stick check strap comprising a piece of leather of substantial width having a slit extending from adjacent one end to its opposite end to form a pair of substantially parallel strips, and means for holding the free ends of the strips in transverse alignment with a greater length of one strip than of the other between the ends of the strap as a whole.

4. A picker stick check strap having parallel side edges and a slit extending intermediately of said edges to form a pair of substantially similar r strips and means securing the strips together in substantial transverse alignment with a portion of one strip presenting a greater effective length than and curving from the plane of the other strip when the strap is extended on a plane surface with its side edges lying in parallel planes normal thereto.

5. A picker stick check strap having parallel side edges and a slit extending longitudinally of the strap between said edges, and means adjacent the strap ends maintaining that portion of the strap between the slit and one side edge longer than the corresponding portion of the strap between the slit and the other side edge, the strap also having a slot near each end adapted for the passage of a bolt for securing the strap to a loom with its ends in overlapping relation whereby when so secured said portions respectively substantially define ellipses having their major axes of different length.

6. A picker stick check strap including a pair of strips of unequal eflective length united adjacent the ends of the strap and each adapted to form a substantially elliptical closed loop when the ends of the strap are in overlapping relation posite extremities of its travel by a picker stick extending within the loops, the major axis of the superior loop being of greater length than that of the inferior one.

CHARLES CARTERBON'D. 

